ACAPULCO, Mexico — Juan Martin del Potro won the Mexico Open on Saturday night for his 21st ATP Tour title, beating Kevin Anderson 6-4, 6-4 to improve to 7-0 against the 6-foot-8 South African.

Earlier in the hard-court event at Princess Mundo Imperial, Lesia Tsurenko successfully defended her women's title with a 5-7, 7-6 (2), 6-2 victory over Stefanie Voegele.

The 29-year-old del Potro won for the first time since successfully defending his Stockholm title last year. Ranked ninth in the world, the 6-foot-6 Argentine player beat Mischa Zverev, four-time Acapulco champion David Ferrer, sixth-ranked Dominic Thiem and fifth-ranked Alexander Zverev to reach the final.

The eighth-ranked Anderson won the New York Open two weeks ago for his fourth career title.

The 28-year-old Tsurenko, from the Ukraine, won her fourth WTA Tour title and first since her victory last year at Princess Mundo Imperial.

"It's such a special tournament for me," Tsurenko said during the trophy ceremony wearing the traditional champion's sombrero. "It was amazing."

Seeded seventh, she was three points from losing the match in the second set in the match that took 2 hours, 45 minutes.

"Stefanie, it was an unbelievable match," Tsurenko said. "It was almost three hours. We both were nervy and we were still fighting to the end. Thanks for this match and for this experience."

The 27-year-old Voegele was making her first appearance in a tour final.

In the men's doubles final, Britain's Jamie Murray and Brazil's Bruno Soares successfully defending their title, beating American twins Bob and Mike Bryan 7-6 (4), 7-5.

Germany's Tatjana Maria and Britain's Heather Watson won the women's doubles in their first tournament together, topping Americans Kaitlyn Christian and Sabrina Santamaria 7-5, 2-6, 10-2.